The KissThrough June 28 at the Loretto-Hilton Center, 130 Edgar Road, Webster Groves.Tickets are $50 to $120 ($15 for students, K-12 teachers and active military, subject to availability).Call 314-961-0644 or visit www.opera-stl.org.

This past weekend Opera Theatre of Saint Louis (OTSL) debuted the final two operas of its 2013 season, a pair that represents the polar ends of the opera spectrum — and two feats our local opera company regularly pulls off with aplomb: bravely premiering modern operas and staging rarely performed gems from opera history.

Saturday saw the world premiere of Champion, an opera co-commissioned by OTSL and Jazz St. Louis. It's the first opera libretto by Pulitzer Prize- and Tony Award-winning playwright and veteran movie scripter (The Witches of Eastwick, The Bonfire of the Vanities) Michael Cristofer. It's also the first opera score by Grammy-winning jazz trumpeter and composer Terence Blanchard. The following night the opera opened its delightful production of an obscure 1876 composition, The Kiss, by composer Bedrich Smetana and librettist Eliška Krásnohorská.

Champion is a gritty drama based on the life of boxer Emile Griffith, who killed Benny "The Kid" Paret in a televised welterweight championship fight in 1962. It features an ultramodern jazz-based score around themes of repressed homosexuality, mental and physical violence and, ultimately, redemption and forgiveness.

The Kiss, on the other hand, is pure showbiz, a fluffy confection of clever staging and charming tunes over a minuscule plot that's just an excuse for fun with singing.

Three singers portray Griffith at the various stages of his life. Jordan Jones, an eleven-year-old boy soprano, shines in scenes from Emile's boyhood, while baritone Aubrey Allicock plays the arrogant, troubled athlete in his prime, performing with crisp assurance and a crystalline voice. But it's bass-baritone Arthur Woodley who owns the night, with his tragic and touching portrayal of the elderly fighter, suffering the ravages of dementia along with lingering anguish over Paret's death and his struggle to come to terms with his own homosexuality.

Denyce Graves, one of the leading mezzo-sopranos of the past twenty years, plays Griffith's wayward, self-serving mother. The bottom of her range is a darkly radiant gem, and she understands jazz singing, too. (She's clearly fan, having named a daughter after Ella Fitzgerald.) But her interpolation of jazz styles into what is at root an operatic performance robs her characterization of continuity.

Champion's score demands fiery intensity, as Blanchard's modernist orchestral take is spiced with references to jazz history in flavors ranging from New Orleans street parades to bebop to modern avant-garde. A trio featuring Blanchard's pianist Fabian Almazan, bassist Robert Hurst III and drummer Jeff "Tain" Watts, augments a cohort from the St. Louis Symphony. (Jazz fans will recognize the latter two from some of Wynton Marsalis' best recordings.) Hurst in particular spectacular: His plucked bass dances at the heart of the score, pulsing with eloquent, swinging precision.

The symphony personnel who back The Kiss, meanwhile, provide solid support and deft propulsion to some of the best vocal performances of this opera season. And singing is ultimately what opera is about.

Soprano Corinne Winters and tenor Garrett Sorenson lead the way as Vendulka and Lukáš, a pair of battling, headstrong lovers. Both have beautifully full tone throughout their ranges and an uncanny ability to meld characterization, emotion and just the right level of energy and comic timing with sure, tuneful singing. Matthew Burns brings a velvety-bass baritone and adept comic timing to the role of Tomeš, Vendulka's father. Mezzo Elizabeth Batton and soprano Emily Duncan-Brown sparkle in supporting roles.

Both operas use cleverly minimalist stage sets to great effect. Champion's ten "rounds" evoke a spare, documentary-film style. The Kiss relies on a few comically simple elements, creative use of a moving strip of stage and brilliant lighting schemes executed by Christopher Akerlind.

If you seek a lighthearted, utterly entertaining evening of musical theater featuring terrific singing and creative staging, The Kiss is your ticket. Champion, on the other hand, offers serious modern theater with complex themes and music to match. Both are well worth your time and cash.